Spinning curve vertices
Model a single tooth.

Add an Array modifier, and a Curve modifier to that tooth object.
Add a new circle curve ShiftA > Curve > Circle
Set the Fit Type of the array modifier to Fit Curve, and target the Bezier Circle (added in step 3). Also set the Object of the curve modifier to the Bezier Circle.



If the teeth overlap, you can scale the circle to get the teeth to line up perfectly.